DE102009055740A1 - Extension element for clamping ratchet, has extension body, at whose one end support element is arranged for connection with handle of clamping ratchet - Google Patents

Abstract

The extension element (1) has an extension body (2), at whose one end a support element (3) is arranged for connection with the handle (4) of the clamping ratchet, where a handle grip is arranged at the opposite end. The handle grip (6) and the support element are connected together by a resistor element (7) in moving manner around a rotary axis (8). The resistor element is formed according to the type of a beam and a strain gauge is arranged at the resistor element.

Description

The innovation relates to an extension element for tensioning ratchets with an extension body, at one end of a receiving element for connection to the handle of the tensioning ratchet and at the opposite end a handle is arranged, wherein the handle and the receiving element are rotatably connected to each other via a resistance element about a rotation axis.

Extension elements for tensioning ratchets are generally known from the prior art, cf. DE 10 2006 044 024 B3 , The tensioning ratchet described therein comprises a resistance element made of a resilient material, which is chosen such that when using the extension element there is no danger of overloading or damaging the tensioning ratchet. If too much torque is applied to the fulcrum of the tensioning ratchet via the extended lever of the extension member, the resistance element will yield and result in a clearly discernible deflection of the handle relative to the receiving element.

A disadvantage of the prior art is that the extension element is technically complicated to manufacture and in particular the resistance element requires increased production costs. Also, the accuracy of the detection of a defined torque limits.

The novelty is the object of developing an extension element for tensioning ratchets with the features of the preamble of claim 1 such that the extension element produced with little technical effort and the resistance element can be selected in the form of a standardized component and the detection of a defined torque precisely and quickly is executable.

This object is solved by the features of claim 1. Advantageous developments of the invention will become apparent from the dependent claims 2-10.

As the core of the invention, it is considered that the resistance element is designed in the manner of a bending beam and the resistance element at least one strain gauge is arranged such that this relative to a torque between the handle and the receiving element or a slight deflection of the handle relative to the receiving element detected to the rotation axis.

By using a bar-like resistive element, which is such that only a slight bending of the beam takes place over its length, an extension element can be formed, which lacks elaborate spring elements. The fact that the mere bending of the resistance element, the achievement of a defined torque for the operator is difficult to see the resistance element is in operative connection with a strain gauge, which is arranged and configured such that this torque between the handle and the receiving element or a slight deflection of the handle relative to the receiving element detected relative to the axis of rotation. The slight bending of the beam is accurately perceived by the strain gauge and quickly converted via the standing with the strain gauge electronics or evaluation device in an acoustic, optical and / or haptic signal, so that the achievement of a defined torque for the operator to easy and fast Way is recognizable.

In an advantageous embodiment, the flexibility of the bar-like resistance element is designed such that a rotation of the handle relative to the receiving element by <3 ° is made possible. The fact that the deflection of the handle relative to the receiving element takes place in a small angular range such as +/- 2 ° or less, the requirements are reduced to the resistance element. For example, it is sufficient to use a commercially available resistance element for bending stresses in connection with strain gauges. Furthermore, the slight deflection makes it possible to choose a robust resistance element, since the slight deflection also makes it possible to bend the resistance element in the elastic region, even with firmer materials.

Furthermore, it is advantageous if the strain gauge is operatively connected to an electronic evaluation circuit which outputs an acoustic, haptic and / or optical signal upon reaching a predefined limit value of an elongation of at least one side of the resistance element. The electronic evaluation circuit is preferably fed with an energy storage such as a battery or a rechargeable battery. Alternatively, the electronic evaluation circuit can also be operated via solar cells arranged on the extension element. An acoustic signal can be output via a buzzer, an optical signal via an LED and a haptic signal via a vibration element, for example. In addition, it may be advantageous to design the electronic evaluation circuit such that a plurality of different limit values are output in the form of an acoustic, haptic and / or optical signal. For example, when Reaching a first limit, a first LED and when exceeding the first and reaching a second limit an additional LED or a different colored LED switched. In particular, if it is intended to use the extension element according to the invention for different types of tension ratchet (with different maximum permissible torques), it may be advantageous to output different predefined limit values via corresponding signals.

The resistance element may be made of aluminum, for example. By choosing such a material, a robust and weather-sensitive design of the extension element is achieved.

In a further embodiment, the resistance element is provided with a recess. The recess serves primarily to achieve a defined bending of the resistance element upon application of a torque to the handle relative to the receiving element. The recess of the resistance element is preferably designed such that the bending force applied to the resistance element when the handle is designed relative to the receiving element causes a defined elongation on the surface of the resistance element. This is achieved by the recess of the resistance element that a greater elongation at the surface of the resistance element is achieved at a constant torque. This increased amount of strain gives the strain gauge a larger input path to be detected so that the accuracy of the strain gauge values with respect to the torque to be detected is improved.

The expansion strip is preferably arranged in the region of the defined elongation of the surface of the resistance element.

Furthermore, it has proved to be advantageous to place the expansion strip substantially centrally on a surface of the resistance element.

Furthermore, it is provided to arrange the defined elongation of the surface of the resistance element in the region of the strain gauge.

In particular, the strain gauge is arranged centrally on the surface of the resistance element.

In a further advantageous embodiment, two strain gauges are provided, wherein a first strain gauge is arranged on a first and a further strain gauges on one of the first opposing outer surface of the resistance element. Characterized in that not only on the claimed on train surface of the resistive element, but also on the stressed surface under pressure of the resistance element a strain gauge is arranged, can be made a more precise statement about the torque acting on the evaluation of the two strain gauges signals.

Preferably, a strain gauge is placed on the surface of the resistive element that is stressed during bending of the resistive element.

The recess of the resistance element is preferably elongated and the strain gauge aligned in its longitudinal extent substantially parallel to the longitudinal axis of the recess. It is also advantageous if the strain gauge is arranged in the region of the recess of the resistance element and with its first end edge and its second opposite end edge does not extend beyond the boundary edges of the length of the recess. Such a configuration achieves a precise and reliably operating arrangement of the strain gauge relative to the resistance element provided with a recess with relatively little production effort.

In a preferred embodiment, the handle is connected via a lever element in the resistance element, wherein the lever element has an elongated shape and is provided on the end facing away from the handle of the lever with a contact region on which the resistance element is mounted positively. The positive storage of the resistance element with the lever can be done either in the manner of a fixed bearing or a floating bearing. For example, the form-fitting mounting of the resistance element may be formed on the contact region of the lever in the manner of a loose bearing, so that the resistance element is integrated statically determined within the extension element.

The pivot axis of the handle relative to the receiving element preferably extends through the lever element.

A further advantageous measure is when the resistance element is formed with at least one predetermined breaking region, which breaks upon the action of a predefined torque such that a deflection of the handle relative to the receptacle ≥ 3 ° is made possible. This means that it is provided as a "final" overload protection function of the extension element, that the resistance element from a torque to be defined (which of course in amount is greater than that Torque at which the signals are output) the resistive element itself is partially destroyed in order to avoid damage or destruction of the tensioning ratchet on which the extension element is placed. In this context, the resistance element may be provided with a plurality of predetermined breaking areas, so that, after the breakage of the resistance element, it can be re-positioned in the extension element in such a way that a second predetermined breaking area forms the predetermined breaking area in the operative position. This makes it possible to carry out a plurality of predetermined fractions with a resistive element.

In this context, it is also advantageous if the resistance element is releasably secured within the extension element, preferably in a non-positive or positive connection, which allows the operator of the extension element easy replacement of the resistance element.

The invention is explained in more detail with reference to embodiments in the drawing figures. These show

1 a schematic representation of the extension element according to the invention for tension ratchets;

2 a schematic representation of the resistive element, the lever and the strain gauge in side view;

3 a schematic representation of individual parts of the extension element according to 2 in the plan view.

The basic structure and use of the extension element is in drawing figure 1 shown. It can be seen that the extension element 1 with an extension body 2 is provided, at one end of a receiving element 3 for connection to the handle 4 the tensioning ratchet 5 and at the opposite end a handle 6 is arranged, wherein the handle 6 and the receiving element 3 about a resistance element 7 rotatable (arrow A) about an axis (rotation axis 8th ) are interconnected. The tension ratchet 5 consists of two legs, one of which is a handle 4 and the other as a counterhold 9 is trained. The handle 4 and the counterpart 9 are around the axis 10 the tensioning ratchet 5 rotatably mounted to each other (arrow B).

According to the invention, the resistance element 7 formed in the manner of a bending beam on which at least one strain gauge 11 is arranged. The strain gauge 11 is arranged such that this torque between the handle 6 and the receiving element 3 or a slight deflection of the handle 6 opposite the receiving element 3 relative to the axis of rotation 8th of the extension element 1 detected. Basically, the extension element 1 used to not point the point at which the force is applied to the handle when tensioning the tensioning ratchet 4 the tensioning ratchet 5 but on the handle 6 of the extension element 1 to choose. This results from the extension body 2 a larger lever for tensioning the tensioning ratchet 5 ,

To the risk of overloading the tensioning ratchet 5 to reduce, it is provided that when applying too high torque on the tensioning ratchet 5 the extension element 1 the operator recognizes that his grip on the handle 6 applied force is sufficient and / or too high.

The bar-like resistance element 7 is dimensioned such that a rotation (arrow A) of the handle 6 relative to the receiving element 3 is made possible by <3 °. The signaling of the achieved or exceeded torque is preferably carried out in that the strain gauge 11 over a line 20 with an electronic evaluation circuit 12 is operatively connected when reaching a predefined limit in the expansion of at least one side 13 of the resistance element 7 an acoustic, haptic and / or optical signal outputs.

In a further development of the invention, in the event that the extension element 1 with tension ratchets 5 different dimensions and / or different load capacity, in particular with a different length of the handle 4 , to be used with a selector switch 21 be provided with the electronic evaluation circuit 12 interacts and over different limits for different Spannratschen 5 or lever length of handles 4 can be adjusted. On a scale of the selector switch, for example, different ratchet types or maximum ratchet loading limits and / or different handle lengths or breaking loads can be specified so that the user is able to variably predefine the limit according to a particular type of ratchet.

As can be seen in the illustrated embodiment, the strain gauge is 11 on bending the resistance element 7 Tensile stressed surface 13 of the resistance element 7 arranged. Especially if that extension element 1 both in a first and in a second by 180 ° to the first rotated alignment equivalent acting on a tensioning ratchet 5 it is advantageous if the extension element 1 at least two resistance elements 7 includes, on a top and bottom of one or more resistive elements 7 are arranged. This allows for torque application between the handle 6 and the receiving element 3 , both at a positive and at a negative torque or at a first positioning of the extension element 1 on the tensioning ratchet 5 and a second 180 ° to the first twisted (rotated about the central longitudinal axis of the extension member) positioning of the extension element 1 on the tensioning ratchet 5 both times the torque through the strain gauges 11 is detectable.

In the illustrated embodiment according to drawing figure 1 and 2 is the handle 6 of the extension element 1 via an elongated lever element 14 with the resistance element 7 connected. The resistance element 7 is in turn via an abutment 15 with the extension body 2 connected, so that in this case the receiving element 3 and the extension body 2 form a stiff unit and torque detection across the strain gauge 11 around the axis 8th he follows. The lever element 14 indicates at its the handle 6 opposite end face 16 a contact area 17 on, on which the resistance element 7 is mounted positively. In the illustrated embodiment, the contact area 17 designed in the manner of a floating bearing. The rotation axis 8th passes through the lever element 14 ,

Furthermore, it is provided that the resistance element 7 a recess 18 has, which is designed such that the deflection of the handle 6 relative to the receiving element 3 Applied bending force on the resistance element 7 a defined elongation at the surface 13 of the resistance element 7 caused. The defined elongation of the surface 13 of the resistance element 7 in the region of the strain gauge 11 can by a corresponding design of the recess 18 be set. Thus, by a corresponding configuration of the recess 18 It allows a defined elongation of the surface 13 of the resistance element 7 to achieve when applying certain torques. For example, the recess 18 in the resistance element 7 elongated and the strain gauge 11 in its longitudinal extension 19 substantially parallel to the longitudinal axis of the recess 18 aligned, cf. Figure drawing 3 ,

In drawing figure 3 are those in drawing figure 2 illustrated elements of the extension element 1 shown in plan view. It can be seen that the extension element 1 also with two resistor elements 7 . 7 ' may be provided, wherein the first resistance element 7 a strain gauge 11 on the top 13 and the second resistance element 7 ' a strain gauge 11 on the bottom (not visible), so it is achieved that both positive and negative torques on the strain gauges 11 and a corresponding evaluation circuit 12 are detectable on train loaded surfaces. It can also be seen that the strain gauges 11 essentially in the middle of the surface 13 of the resistance element 7 are arranged.

LIST OF REFERENCE NUMBERS

1

extension element

2

extension body

3

receiving element

4

Handle v. 5

5

ratchet

6

handle

7

resistive element

8th

axis of rotation

9

backstop

10

Axis v. 5

11

Strain gauges

12

evaluation

13

Side / surface

14

lever member

15

abutment

16

front

17

contact area

18

recess

19

Longitudinal extension v. 11

20

management

21

selector

A

arrow

B

arrow

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006044024 B3 [0002]

Claims (10)

Extension element ( 1 ) for tension ratchets ( 5 ) with an extension body ( 2 ), at one end of a receiving element ( 3 ) for connection to the handle ( 4 ) of the tensioning ratchet ( 5 ) and at the opposite end a handle ( 6 ), wherein the handle ( 6 ) and the receiving element ( 3 ) via a resistance element ( 7 ) rotatable about a rotation axis ( 8th ), characterized in that the resistance element ( 7 ) is formed in the manner of a bending beam and on the resistive element ( 7 ) at least one strain gauge ( 11 ) is arranged such that this torque between the handle ( 6 ) and the receiving element ( 3 ) or a slight deflection of the handle ( 6 ) relative to the receiving element ( 3 ) relative to the axis of rotation ( 8th ) detected. Extension element according to claim 1, characterized in that the flexibility of the beam-like resistance element ( 7 ) is dimensioned such that a rotation of the handle ( 6 ) relative to the receiving element ( 3 ) is made possible by <3 °. Extension element according to claim 1 or 2, characterized in that the strain gauge ( 11 ) with an electronic evaluation circuit ( 12 ) is operatively connected, which upon reaching a predefined limit value of an elongation of at least one side ( 13 ) of the resistance element ( 7 ) emits an acoustic, haptic and / or optical signal. Extension element according to one of claims 1-3, characterized in that the resistance element ( 7 ) a recess ( 18 ), which is designed such that upon deflection of the handle ( 6 ) relative to the receiving element ( 3 ) applied bending force on the resistive element ( 7 ) a defined elongation at the surface ( 13 ) of the resistance element ( 7 ) caused. Extension element according to claim 4, characterized in that the recess ( 18 ) in the resistance element ( 7 ) is elongated and the strain gauge ( 11 ) in its longitudinal extent ( 19 ) substantially parallel to the longitudinal axis of the recess ( 18 ) is aligned. Extension element according to claim 4 or 5, characterized in that the strain gauge ( 11 ) in the region of the recess ( 18 ) of the resistive element ( 7 ) is arranged and with its first end edge and its second opposite end edge does not extend beyond the boundary edges of the length of the recess. Extension element according to one of the preceding claims, characterized in that the strain gauge ( 11 ) on the bending of the resistive element ( 7 ) tensile stressed surface ( 13 ) of the resistance element ( 7 ) is arranged. Extension element according to one of the preceding claims, characterized in that the handle ( 6 ) via a lever element ( 14 ) with the resistance element ( 7 ) connected is. Extension element according to claim 8, characterized in that the lever element ( 14 ) has an elongated shape and at the handle ( 6 ) facing away from the front side ( 16 ) of the lever element ( 14 ) with a contact area ( 17 ), on which the resistance element ( 7 ) is mounted positively. Extension element according to one of the preceding claims, characterized in that the resistance element ( 7 ) is formed with a predetermined breaking range, which breaks upon the action of a predefined torque such that a deflection of the handle ( 6 ) relative to the recording ( 3 ) ≥ 3 °.

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